C-405 light through ADF

[Rusty.Harris]

Tech just called me saying he has a C405 with "light copies" through the ADF.
Off the glass, images look fine.
He did a software update to version 68.69.51
When he did a color calibration adjustment, he got an error 3-704
According to the rap in prolibro, it says to update the firmware.
He showed me samples of what he was dealing with and it almost looks like
the scanner position under the slit glass might be off just a bit and not aimed
dead center for the document. Is that possible? I know on other brands,
when people call with ADF "lines on copies" due to debris on the slit glass,
you can shift the position of the scanner to get out of the debris field.

Any other suggestions?

[Gaffers01]

Have you tried a double sided copy (through doc feeder) to see what the second side looks like?

The IIT assy on these are known for being flakey, Ive replaced quite a few with different issue's.